Compositions for making substrates, e.g., fibrous substrates such as leather and textiles, oil- and water repellent and/or to provide other properties such as stain repellency and/or stain release to the substrate have been long known in the art. Fluorochemical compounds have been well known as being highly effective in providing oil and water repellency to substrates and in particular textile and leather substrates. A variety of fluorochemical compositions are known and have been used to render substrates oil- and/or water repellent as well as to provide stain resistance or stain release properties thereto. For example, the fluorochemical composition may be based on fluorochemical acrylates or methacrylates that are derived from the polymerization of an acrylate or methacrylate monomer that has a fluorinated group and optionally one or more non-fluorinated monomers. Such compositions have been described in for example U.S. Pat. No. 3,660,360, U.S. Pat. No. 5,876,617, U.S. Pat. No. 4,742,140, U.S. Pat. No. 6,121,372 and U.S. Pat. No. 6,126,849 and EP 1 329 548.
Alternatively, the fluorochemical compound contained in the fluorochemical composition may be derived from a condensation reaction of a fluorochemical compound having an isocyanate reactive group such as, e.g., a hydroxy group and a polyisocyanate compound and optional non-fluorinated co-reactants as disclosed in, e.g., U.S. Pat. No. 5,910,557.
U.S. Pat. No. 6,525,127 discloses fluorochemical compositions that are based on a fluorochemical compound comprising: a fluorochemical oligomeric portion comprising an aliphatic backbone with a plurality of pendant fluoroaliphatic groups, each fluoroaliphatic group having a fully fluorinated terminal group and each independently linked to a carbon atom of the aliphatic backbone through an organic linking group; an aliphatic moiety; and a linking group which links the fluorochemical oligomeric portion to the aliphatic moiety. The compositions are taught to provide desirable oil, water and stain repellency to fibrous substrates.
The known fluorochemical compositions are available both as solutions or dispersions in an organic solvent as well as aqueous based compositions wherein the fluorochemical composition is typically dispersed in an aqueous medium. Water based compositions are generally preferred from an environmental point of view.
One of the disadvantages of water based compositions is that they typically require a heat treatment at elevated temperature of, e.g., 60° C. or more upon application on a substrate to achieve optimal properties such as oil- and/or water repellency properties. Accordingly, such aqueous compositions are not very suitable for use by a consumer that wants to treat a substrate such as for example a leather jacket or a garment. Treatments carried out by consumers are typically done at room temperature, e.g., by spraying the composition on the substrate desired to be treated and then leaving that substrate to dry at ambient conditions.
It would now be desirable to improve aqueous based fluorochemical compositions. In particular it would be desired to develop aqueous compositions having a fluorochemical compound that can be applied at ambient conditions without the need of a heat treatment step while still achieving good repellency properties such as oil and/or water repellency properties on the substrate. Preferably the obtained repellency properties would be comparable to those achieved upon heat treatment. Desirably the composition is environmentally friendly and is substantially free of flammable compounds. It would furthermore be desirable that the compositions can be manufactured in an easy and convenient way and at economically favorable conditions. Desirably, the composition can be easily applied by a consumer such as for example by spraying, wiping or foaming the composition on a substrate. Desirably, the compositions are effective for treating fibrous substrates such as textiles and leathers.